Two filament baseless cartridge lamps are known and may for example be manufactured as described in U.S. Pat. No. 4,061,940 which is incorporated herein by reference. A cooperating socket for the baseless bulb is also described in the foregoing patent; however, the socket disclosed is not practical for mounting the lamp in a reflector and in general would not allow ease of replacement from the rear of a typical reflector assembly. While the socket described in the patent, in cooperation with the lamp, solved general significant problems in the prior art, particularly in terms of registration of the filaments in relation to the mounting supports, there remain other problems associated with this socket as well as with sockets for based bulbs. For example, whenever the lamp is operated in an environment where shocks and vibration occur, as in a vehicle headlamp, the life expectancy of prior art filament bulbs has been considerably reduced. A minor bump, in many instances, can destroy the lamp simply by causing the filament to snap.